The present invention relates to an antenna with high scanning capacity. It relates more particularly to an antenna for use in a telecommunications system, in particular a telecommunications system using satellites.
Antennas are frequently needed, in various applications, to receive signals from a mobile source and/or to transmit signals to a mobile receiver or target. Such transmit and/or receive antennas are usually active antennas made up of stationary radiating elements in which the direction of the radiation pattern can be varied by varying the phase of the signals feeding the radiating elements.
That technique cannot produce satisfactory radiation patterns for large squint angles, i.e. for directions departing significantly from the mean transmit and/or receive direction.
A source or a receiver can also be tracked using a conventional antenna moved by a motor. That type of antenna with mechanically movable elements and a motor is not suitable for all applications. In particular, it is preferable to avoid the use of any such antenna in space applications, for reasons of reliability, overall size, and weight.
The invention remedies those drawbacks. It provides an antenna with a high scanning capacity and with a satisfactory radiation pattern at large squint angles, and which does not require any moving parts.
The antenna of the invention comprises a set of static radiating elements commanded to perform scanning and reflector means to amplify the scanning angle of the radiating elements. The reflector means include two reflectors having a common focus, the first reflector receiving the beam transmitted by the set of radiating elements and the second reflector receiving the beam reflected by the first reflector.